Proving Who's Best
by 1thousandminus7
Summary: Request fic for xXxCorpseGoreSickoxXx. When forced to work together for some dumb school project, what are two rivals to do? Featuring King Douchebag himself and everyone's favourite psychopath. Basically shameless smut. Have fun!


**A/N: So yeah. More Corpse Party. Except... Less corpses this time. I have started a story involving Morishige, but I haven't really got any proper storylines together yet, so chances are if I posted it it'd be a long time until it got updated. Let me know if you want it up anyway :P**

Also, for those who are wondering if this means I've put Reborn on hold, no I haven't, I just wanted to do this. Next chapter is in the works, I promise. Anyway. Enjoy!

"For this project, I will put you into pairs, and you will work together to turn it in." A collective groan went through the class. I sighed a little. I never liked group projects. The others just got in my way. Hopefully I'd get put with someone who wouldn't argue with my ideas too much, and who would just let me get on with it. The teacher rattled off names, and I watched my classmates as they either grinned at each other and high fived, shrugged it off or reluctantly accepted it. Kurosaki had been looking hopeful, glancing in my direction, but his hopes were dashed as he was paired with Ohkawa.

"Kizami and Shimada," the teacher read in a bored tone. I couldn't help the gasp of shock as Shimada yelled " _What_?!"

"I'm sorry if you don't like it, but your grades have been slipping. With any luck, working with Kizami will put you back up to speed. This is an academic project, not a chance to socialise."

The redhead made his frustration known, but didn't argue back any more, much to everyone's relief. I was fighting a rising sense of irritation. I just had to get paired with him, didn't I? The guy had been treating me as though I were some sort of nemesis of his ever since we met, and often went out of his way to set up some competition he could use to prove he was better than me. I had no doubt he'd be fighting my ideas the whole way. This would certainly be a test of my patience.

"Right. I want this assignment completed before Friday next week. That means that you will have to do some work outside of school. With that in mind, I won't be setting any homework, as you'll be doing this instead." The relief in the room was tangible. Those who had been paired with their friends looked ecstatic. "Alright. You know the brief. Come to me if you have questions. Class dismissed." The scraping of chairs against the floor filled the room, and partners immediately went to speak to each other, and arrange plans for doing the project. Shimada was leaning against the door frame as the others left, looking sulky. It took a second for me to realise he was waiting for me. I'd half expected him to just run off without saying a word to me.

"Alright Kizami, what's your magical plan to make me a straight-A student then?" He joined me as we left the classroom, walking beside me down the hall.

"You act like I decided this. I'm in the same position you are." I gave him a look of disdain. "I'm going to do the project. If you decide to help, then so be it, if not, then at least I'll be able to get it done quickly."

"What's that supposed to mean?" He looked affronted, glaring at me. "You know, I'm pretty fucking smart. I'm just not a kiss-ass teacher's pet like you are."

I sighed. "Well, we'll need a plan then. When are you free?"

"Uh… Well this Saturday the agency wants me for a shoot so I'll be busy." I didn't miss his smirk. I rolled my eyes.

"What about Sunday?"

"Sure."

"Your place or mine?" "I'm pretty sure mine's bigger. Plus I don't have any annoying siblings to worry about."

"Mm…"

"Be at mine at one, okay? You know where it is."

"Yeah."

With that, he walked off. I couldn't help but smile a little at his attitude. He did amuse me sometimes. Especially when he deluded himself into thinking he could beat me at something.

Sunday crept up on us quickly. I had already done a decent amount of background research surrounding the subject, and had with me my notes and textbooks as I headed up to the front porch. Shimada hadn't been lying; his house was pretty big. I imagined that his job brought in a decent amount of cash. It was only 12:30, but I was eager to get started, and had nothing else going on, so I decided to come early. I rang the doorbell and waited. Nothing happened for a couple minutes, so I rang again. This time I heard an indignant yell from behind the door.

"Gimme a sec, I'm coming!"

About thirty seconds later, a very shirtless Shimada Kai answered the door, scrubbing furiously at his long red hair with a towel, sweatpants hung low on his hips. "Kind of a bad time here-" He started, and then it registered who was standing on his doorstep. Shock crossed his face, and a blush appeared on his cheeks before he turned hostile.

"What the fuck, Kizami? Didn't I say one p.m?"

I shrugged, smirking a little at his reaction. "I was in the area. Should I go?"

"No!" He answered abruptly, before catching himself. "Nah, there's no point. You're here now." He threw his towel over his shoulder, stepping aside to let me in. "Besides, it's not like you haven't seen me shirtless before."

I looked around as I entered. The place was surprisingly neat. I supposed that was probably his parents, not him. Speaking of which…

"Are you the only one here?"

"What? Oh, yeah. Everyone's busy so it's just me today."

I nodded. Shimada shut the door behind me, and ran up the stairs. I followed him at my own pace, and he stopped outside an open doorway to wait for me.

"Jeez. take your time why don't you?" He disappeared inside. I found him inside lounging across a large bed with red sheets. His room was spacious, almost luxurious. Not as tidy as the rest of the house, but not appalling. There was a mounted flat-screen TV across from his bed, and a bookshelf haphazardly strewn with everything from textbooks to horror novels to manga. Below it were a couple of beanbags. A desk to one side covered in assorted paper and stationary below a corkboard covered in clippings from magazines, mostly featuring him in various outfits and states of undress. I also noted, with some surprise, that buried amongst the many images of himself was the cover of the magazine I was on, thanks to the bet he lost. I will admit, I did look good in that picture. I wondered why he had it. A reminder? Motivation to do better? Or something else?

"Welcome to Casa del Kai." He made a sweeping gesture. "Make yourself at home."

I pulled out his desk chair. It had his school blazer draped over it. Sitting down and neatly stacking his papers on his desk to clear space, I pulled out my own work and began going through it.

"Nice isn't it?" I looked over to him, and he smirked. "I bet it's bigger than yours."

"Everything has to be competition with you, doesn't it?" I noted with a small smile.

He glared at me. "I bet you're just jealous."

Yet again, I found myself rolling me eyes at him. "Right. So I've written some notes-"

"Do we have to start work right away?" He interrupted me.

"That's what I'm here for, isn't it?" I replied coolly.

"Yeah but you're here early. I don't wanna start yet."

I paused for a moment, then put down my papers. "What else did you have in mind?"

"I dunno." There was a brief silence. "Why the hell are you always so studious anyway? Don't you ever take time off?"

"I do. But I care about my grades."

"Why?"

I blinked. "Because they matter. Without them you can't get a decent job or go to college. Plus knowledge is a valuable tool."

"I know things." He protested. "Just because I ain't gettin' as good grades as you don't mean I ain't as smart as you. I'm just as good as you are."

"I've beaten you in every challenge you've set me." I stated plainly, not as a show of arrogance but as pure fact.

He huffed, sitting up. "I just haven't found the right challenge yet." I raised an eyebrow, amusement in my features.

"Oh?"

"Like…" He paused, thinking. Then he seemed to get an idea. "I bet I've been with more girls than you."

I frowned. I had never really bothered with the whole dating thing. Relationships just seemed a waste of time to me. Sure, others had shown interest, but I had never reciprocated their feelings. He noticed my hesitation and perked up, a disbelieving smile on his face. "No way. I'm right, aren't I? I can't believe it…"

"You didn't believe it when you said it?" I deflected. "Then why did you ask?" But he wouldn't let it go.

"You know what, I don't think you've ever had a girlfriend, have you?" He laughed.

"I've never wanted one." I stated. I knew this was a dumb thing to get defensive about, but the way Shimada was gloating about it got under my skin.

"What, are you gay or something?" He smirked."You and Kurosaki've always been close."

I blinked. "Excuse me?"

"Nah, I'm pretty sure he's got his eye on Mitsuki. You've never had a boyfriend either. Have you even ever kissed anyone?"

"Is that any of your business?"

"Ha!" He stood up, looking smug, advancing towards me. "I told you, Kizami. I told you I was better than you." Okay, this was beginning to irritate me.

"I don't see how that is relevant to anything important." I told him shortly.

"It's relevant because I finally beat you at something."

I glared at him. "I could be better. You don't know that."

"Oh come on, Kizami. If you've never done it how the hell could you be better than me?" He crossed his arms, smirking. I wanted to wipe the smug look from his face. Standing, I used my height to my advantage, looking down at him.

"What? Am I pissing you off? Are you jealous?" He didn't back down. Instead, he met my eyes fiercely.

My first instinct was to hit him. But no, that'd get me in trouble again. They'd put me back on the meds. Instead, I did the only other thing I could think of to shut him up. I grabbed him by the throat, hesitating for only a split second as his expression changed from smug to shocked, and then kissed him.

I was unpracticed, yes, but I was a fast learner. I felt his hands on my chest, as though he were going to push me away, but I didn't stop. My hand went from his throat to the back of his neck, and I parted his lips with my tongue, controlling his every movement with my own. What little resistance he put up quickly left him, and I was pleasantly surprised when he let me dominate the kiss. I couldn't deny, there was something… pleasing about the way his lips moved on mine. His hands began to move, tracing their way over my body, but I stopped it before they could go anywhere, stepping back. Shimada leaned forward as I moved back, trying to stop me from breaking the kiss. I pulled away anyway. He opened his eyes, indignation on his face as he looked up at me. His cheeks were flushed and his breathing was heavier than usual.

"You bastard. You can't just leave me like that."

"Why not?"

He blushed, and I glanced over him, smirking just a little when I noticed the reason why. Crossing his arms, looking more than a little uncomfortable but making no attempt to cover himself, glaring at me pointedly.

"That's not fair."

"What's not fair?" I decided I liked him more like this. I so obviously held power over him, and so I decided to abuse that power, moving towards him once more. He took half a step away from me as I walked around him, which only made my predatory instinct kick in even more. He had his back to me now, and I moved up against him, simultaneously reaching a hand around to brush against his jawline. Applying the tiniest amount of pressure, I tilted his head back so it rested on my shoulder, exposing his throat. My other hand snaking around his middle, I leaned in, my breath on the side of his neck. His own breathing hitched, and I could practically hear the racing of his heart with how obvious his reactions were. I murmured his name, my voice purposefully low and loaded with seduction. His first name, not his surname.

"Kai…"

He gasped in a shaky breath as I pressed my lips to the spot just below his ear, the tip of my finger tracing a feather-light line down his throat. I could feel him trembling. It excited me.

My other hand trailed over his hipbone, down to where it dipped below the waistband of his boxers.

"Fuck, Kizami…" He practically moaned. "Don't be such a goddamn tease…"

In response, I let my fingers slip into his underwear, feeling the rough texture of his pubic hair under them. When my hand finally wrapped around his cock, he jerked, bucking into my grip. I began to stroke him slowly, experimenting to find exactly what got the best reactions out of him. Every now and then I'd do something that would cause him to inhale sharply, pressing himself back against me. He had started to move his hips with my hand, and I let him, though I kept the rhythm slow. I teased his tip with my thumb, feeling slickness there, and his gasps turned into audible noises of pleasure.

"More, Kizami, please…" He begged. "Faster…"

I tightened my grip, loving the whine I got for my efforts, but still I kept the pace torturously slow, driving him crazy. After long minutes of brutally dragging it out, refusing him what he wanted and getting more and more wanton moaning and gasped obscenities in return, I felt him tense, his breathing irregular. Sensing that he was close, I finally relented, speeding up the pace, wanting to push him over the edge.

"Ah… Shit-!" His whole body jerked, and he thrusted forward a couple more times, suddenly panting like he'd just run a race as he came all over my hand. I didn't stop as he cried out, twitching and almost going limp, my arm around his chest the only thing keeping him from falling to his knees. His body wracked with pleasure, he seemed to be unable to speak, fighting to get his breath back. I slowed and stopped, letting him recover.

"God…" He leaned against me, his eyes half-closed and his lips parted. I lifted my dirtied hand to his face. He obliged, sticking out his tongue and licking my hand clean. At this point I bet he would have done anything I asked him to. Satisfied with his ministrations, I turned him to face me, kissing him again. His tongue was bitter and salty, and he sighed into my mouth. Breaking away, he looked up at me, his expression a mix of lust and annoyance.

"Kizami…"

"Mm?" I brushed his hair from his face gently.

"You ruined my underwear."

I laughed. Somehow even now he found an excuse to be irritated with me. "Take them off then."

He narrowed his eyes at me. "You're still fully dressed, idiot. That's not fair."

I took his chin into my hand, being a touch more forceful. "So do something about it."

He did. Slipping out of the remainder of his clothes, he pressed his naked body to mine, and began unbuttoning my shirt, trailing kisses over my collarbone and chest as he pushed the black material off my shoulder, exposing my skin. I shrugged it off completely, for the first time appreciating what another human could do for me. I should do this more often.

His hands ghosted over me, cold to the touch. When they reached my jeans, I found myself eager for more, excited for him to touch me properly. I gasped a little when he bit down on the side of my neck, and he looked up at me, smirking, before doing it again. I allowed him a low hum of appreciation, but no more than that. In pursuit of a better reaction, he bit down harder, unzipping my jeans and reaching in at the same moment.

"Ah…" I couldn't hold it back. He grinned at me, and then did something I didn't expect; he dropped to his knees before me. I watched him, surprised but pleased, as he pulled out my hard cock, stuck his tongue out, and licked. The sensation was sudden, and strong. He watched my face as he took me into his mouth, and it was obvious that he knew what he was doing. I felt my control slipping. My fingers entangled themselves in his long hair, pulling a little. I had to bite my lip to keep from moaning as he teased me with the tip of his tongue, running it too lightly over the slit and then going down on me properly, bobbing his head back and forth. Using his mouth and hand simultaneously, he worked the whole length, and I could feel the tension like fire in the pit of my stomach. I thrust into his mouth, wanting, needing more, my thoughts no longer fully coherent. I hadn't been prepared for the intensity of the feeling. It was unlike anything I could do to myself, and it was, dare I say it, addictive. Every time he moved, he went a little further, until I could feel the motions of his throat as he swallowed around me, so warm and wet and delicious. I was close, I knew it. The heat was building in me, and as he met my gaze with lust-filled eyes, I gritted my teeth, taking control and face-fucking him with a rhythm more suited to my needs than what he had been giving me. My breath caught in an uneven moan, the pleasure reaching it's peak, and I came. He gagged a little, pulling back as I finished. Now it was my turn to be breathing hard, feeling lightheaded. I had to take a moment as my vision whited out, dizziness washing over me, as I did my best to fight the weakness in my knees. Kai stood, wiping trails of white from his lips and chin. He grinned at me as he licked it from his fingers.

"I bet the great Kizami Yuuya couldn't do that."

"Not without practice." I conceded, then gave him a look. "Something you've obviously had."

He blushed again. "Shut up. So I've slept with a few guys. Big deal." His eyes flickered over my body. "You're still not naked, idiot."

Letting out a soft laugh, I kicked off my shoes and stripped completely, standing before him.

"Happy?" He stepped back, getting a good look. I knew I was an impressive specimen, and that showed on his face as he took it all in.

"Goddamn it Kizami…" He sighed, and then turned to a chest of draws, opening the top one and taking something out, then facing me and holding it out, hand on hip. I took it from him.

"Just one time, okay? And you tell no one I let you do this." I looked down at the little square packet in my hand, and smirked. He sighed, falling back onto his bed, looking up at me expectantly. I climbed on top of him, and he pulled me down into a kiss, his hands grasping at my back as I felt his whole body against mine, nothing between us but sweat. His teeth grazed my lip, and when we broke apart his lips were glistening and full, his green-blue eyes regarding me with desire and… adoration?

I lowered my lips to his neck once more, and let my hand run over his body. He shivered a little, and I copied what he'd done earlier, biting down hard enough to leave a mark. He gasped, and as my hand reached his hip, he spread his legs for me. Before I could go any further though, he stopped me.

"Wait." He pushed me off briefly, reaching over for a bottle on his bedside table before returning to his position and pulling me back on top of him. He held it up. "You're not fucking me dry. No way in hell."

"Of course." I took the lube, squirting some on my fingers. I would have, in all honesty. But it was probably easier this way. Putting the bottle to one side, I leaned over him, one hand holding me up as the other teased his entrance. I looked him directly in the eye as I pushed a finger inside him. His lips parted in a silent gasp as I did so, his eyes widening ever so slightly. If it hurt, he didn't make that known. I began to experiment, thrusting it in and out, trying different angles. He closed his eyes, bathing in the sensation, until I touched something inside him that made him jolt. He moaned, and I continued to rub the newfound spot, feeling his muscles tighten around my finger at the pleasure.

"More…" He muttered. I obliged, adding a second finger. This time, he let out a whine of pain. That didn't stop me, though, as I stretched him open, ready to take me. I was hard again, this panting, heated mess of a man below me invoking desires I didn't know I had. And as I finger-fucked him, I found the condom he'd handed me with my other hand, tearing it open with my teeth. He helped me get it on, and then kissed me again, pushing himself down onto my hand. Strained noises came from his throat as my fingers pressed against his prostate, my tongue in his mouth.

Finally I couldn't wait any longer, pulling my slick fingers out of him and murmuring in his ear, "On your hands and knees." He did as he was told, rolling over and pushing his ass into the air for me, legs wide. I lined up as he watched me over his shoulder, and thrust into him roughly in one move. He cried out, clenching at his pillow. I couldn't hold back a moan, the heat and pressure around my cock deliciously satisfying. I only held still for a moment before I started moving, craving the friction. My hand pressed into the small of his back as he braced himself against the headboard, taking my thrusts and responding with movement of his own. I was rough with him, but he seemed to love it, crying out and pushing back against me. With one hand grasping the head of his bed, he stroked himself with the other, moaning my name.

"Fuck, Shimada…" I head myself say in a rough voice, instinct taking over as I fucked him hard. Changing my angle, I found his prostate once more, making him scream in pleasure as I hit it over and over. He was such a vocal lover, and I loved it. I sped up, the heat building once more. My fingernails dug into his hips, and he tensed, so tight around me I was sure he could feel every imperfection.

"Oh, God, Kizami! Fuck me, fuck me ha-a-AH!" He couldn't finish as he lost rhythm, coming all over his sheets. My own orgasm wasn't far off, and I didn't slow down, pushing myself to the edge and drawing out his orgasm as long as possible at the same time. my thrusts fell out of time, the tension in my body uncontrollable, and I let go, thrusting deep inside him as I came. My cry of pleasure turned into panting, and I collapsed on top of him.

We stayed like that for a few minutes, an exhausted, sweaty mess, my chest against his back and my cheek resting on his shoulder, until he moved a little, indicating he wanted me to get off. I reluctantly pushed myself up, pulling out of him. He twitched, and then rolled onto his back, looking up at me. I took off the condom, putting it with the lube on his bedside table, and then kissed him again, this time pulling him on top of me. His long hair brushed my cheek as he responded, and I brushed it back with one hand. Eventually he stopped, pulling away and looking at me in a way he never had before. His eyes met mine for a moment, and then he lay down half on top of me, his legs tangled with mine and his head resting on my chest.

"I give up." He sighed. "You're the best."

I smiled quietly to myself, but said nothing. After all, I'd known that all along.


End file.
